Safety and Efficacy of SCH 503034 in Previously Untreated Subjects With Chronic Hepatitis C Infected With Genotype 1 (Study P03523)

The study was conducted in 2 parts.

Part 1 of the study had 5 arms using weight based ribavirin 800-1400 mg/day and compared:

• PegIntron and ribavirin for 48 weeks (Arm 1 - Control)
• PegIntron, ribavirin, and boceprevir for 28 weeks (Arm 2)
• Lead-in with PegIntron and ribavirin for 4 weeks followed by PegIntron, ribavirin and boceprevir for 24 weeks (Arm 3)
• PegIntron, ribavirin and boceprevir for 48 weeks (Arm 4)
• Lead-in with PegIntron and ribavirin for 4 weeks, followed by PegIntron, ribavirin and boceprevir for 44 weeks (Arm 5)

Participants from Arm 1 receiving PegIntron and ribavirin that were HCV positive after 24 weeks of treatment had the option to receive boceprevir in combination with PegIntron and ribavirin for an additional 24 weeks. All participants from Arm 1 that started boceprevir after Week 24 formed the crossover arm (Arm 8).

Part 2 of the study assessed the safety and efficacy of low dose ribavirin (400-1000 mg/day) and compared:

• PegIntron, ribavirin (800-1400 mg/day) and boceprevir for 48 weeks (Arm 6)
• PegIntron, low-dose ribavirin (400-1000 mg/day) and boceprevir for 48 weeks (Arm 7)

Follow-up for all participants was up to 72 weeks after randomization.

Inclusion criteria

• Age between 18 and 60 years;
• Body weight between 45 and 125 kg;
• Documented chronic hepatitis C genotype 1;
• Liver biopsy with histology consistent with chronic hepatitis and no other etiology for chronic liver disease within of 5 years of Day 1;
• Participant and participant's partner(s) must each agree to use acceptable methods of contraception 2 weeks prior to Day 1 and at least 6 months after the last dose of study medication;
• Written informed consent.

Exclusion criteria

Include, but are not limited to, the following:

• Prior treatment for hepatitis C;
• Co-infection with HIV or hepatitis B virus (HBsAg positive);
• Evidence of decompensated liver disease;
• Diabetic and hypertensive participants with clinically significant ocular exam findings;
• Pre-existing psychiatric condition, including but not limited to:

• Current moderate or severe depression;
• History of depression associated with any of the following:

• Hospitalization for depression;
• Electroconvulsive therapy for depression;
• Depression that resulted in a prolonged absence from work and/or significant disruption of daily functions;
• Suicidal or homicidal ideation and/or attempt;
• History of severe psychiatric disorders (including but not limited to schizophrenia, psychosis, bipolar disorder, post-traumatic stress disorder or mania);
• Past history or current use of lithium;
• Past history or current use of antipsychotic drugs for listed conditions.
• Substance abuse within protocol specified timeframes;
• Pre-existing medical conditions that could interfere with the participant's participation in and completion of the study, including but not limited to chronic pulmonary disease, cardiac dysfunction or immunologically-mediated disease;
• Active or suspected malignancy or history of malignancy within the past 5 years;
• Participants who are pregnant or nursing; participants who intend to become pregnant during the study period. Male participants with partners who are, or intend to become, pregnant during the study period.
• Treatment with any investigational drug or participation in any clinical trial 30 days within Screening;
• Hemoglobin <12 g/dL for females and <13 g/dL for males;
• Neutrophils <1500 mm^3; Blacks: <1200/mm^3;
• Platelets <100,000/mm^3;
• Other clinically significant laboratory test abnormalities.